Attic Insulation and Ventilation

When considering a new roof for your home, it’s important to consider the state of your attic insulation at the same time. If your roof has been leaking or you have had problems with ice dams, your attic insulation may be inadequate or damaged by moisture.

Benefits of Adequate Attic Insulation

Save Money: Proper attic insulation can save 15-50% on your home’s heating and cooling bill. Heat flows from warmer to cooler spaces, and the primary purpose of insulation is stop the flow. Heating and cooling costs are reduced when heated air doesn’t go through the roof in winter, and when the sun’s heat cannot penetrate deeper into the house in summer.

Save the Environment: Even if you’ve got money to burn, attic insulation reduces your home’s carbon energy footprint. At Duval, we use only blown-in cellulose insulation, an environmentally friendly insulating material. If your old insulation dates from before 1990, make sure it isn’t made of asbestos-containing vermiculite.

Protect Your New Roof: Adequate insulation reduces the roof deck temperature which optimizes the life of asphalt shingles and minimizes the occurrence of damaging ice dams. Proper ventilation can help prevent moisture which could otherwise reduce the effectiveness of the insulation and lead to mold, mildew, or even structural deterioration.

How Much Attic Insulation Do You Need?

R-Value Measure

If you have access to your attic, you can do a quick check of your insulation levels. If the insulation is below or level with the joists, then you need to add more.

R-value is a measure of insulation’s ability to resist heat transferring through it. The higher the R-value, the better the resistance. In our part of New England, R49 is the minimum recommended value. R49 translates to a depth of approximately 13 – 18 inches for blown-in cellulose insulation (the type installed by Duval Roofing).

Proper Attic Ventilation

Attic VentilationA balanced roof ventilation system will provide nearly equivalent amounts of ventilation area at the eave (soffit) and at or near the ridge. Properly installed ridge and soffit vents rely on natural convection to promote the ventilation that will keep the roof cool.


Learn more about Duval’s attic insulation installation services in Reading and surrounding towns on Boston’s North Shore.